Froth-flotation concentration of ores



of an alkaline-earth metal xanthate.

Patented May 29, 19 28.-

UNITED STATES CORNELIUS H. KELLER, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR TO MINERALS SEPARATION NORTH AMERICAN CORPORATION, OF NEW YORK, N. 1., A CORPORA- TION OF MARYLAND.

FROTH-FLOTATION CONCENTRATION OI 03.155.

R0 Drawing.

This invention relates to ore concentration. According to this invention the frothflotation concentration of ores is carried out by the aid of alkaline-earth metal xanthates or of impure xanthates carrying more or less The invention is well adapted to be used where xanthates are locally produced at mines, and

is herein disclosed as carried out with the use of calcium and barium xanthates. These xanthates are especially useful in coneen-.

trating iron-bearing ores, where it is desired to obtain a product low in iron.

An impure calcium xanthate was made by agitating together for a half hour twenty grams of calcium oxide, seventy-five grams of water, ten cubic centimeters of carbon disulphide, and fifteen cubic centimeters of alcohol. This was successfully used about a week later in the froth-flotation concentration-of Anaconda ore in neutral circuit.

Another freshly prepared lot of this impure xanthate was used in the following test on Utah Copper Company ore. The ore was reground for fifteen minutes with six pounds of calcium oxide per ton to pass 80 mesh, made into a pulp with water, and then agitated for ten minutes with 0.2 pounds of steam distilled pine oil and 0.6 pounds of the foregoing impure xanthate, both per ton of ore, and a froth concentrate separated.

Theresults are shown in the following table:

An impure vxanthate was made by reaction between sodium carbonate, water, l1m e, carbon disulphide and alcohol to contain about 5% each of calcium xanthate and -calcium thiocarbonate, and some sodium xanthate, and was used in the following test onUtah Copper Company ore. The ore was reground for fifteen minutes with "six Application filed March 24, 1927. Serial No. 178,145.

Assays Recoveries 'Wt.

Cu. Fe. Cu. Fe.

Per cent Per cent Per cent Per cent Per cent Heads 100.0 0. 94 3. 7 Conc 7. 3 10. 04 23. 5 78. 2 46. 8 'Ialls 92. 7 22 2.1 21. 8 53. 2

Another impure xanthate mixture was made like the last-described, but b a mixture so modified as to yield a product containing about 25% each of calcium xanthate and calcium thiocarbonate, and some sodium xanthate and sodium thiocarbonate, and was used in the following test on Cornstock silver ore.

The ore was reground to pass 120 mesh, made into a pulp with water, and then agitated for fifteen minutesv with 0.4 pounds of Barret #2 coal tar creosote, 0.4. pounds of cresylic acid, and 0.15 ounds of the impure xanthate mixture, a l per ton of ore, to yield a lead-bearing froth concentrate. The remaining pulp was then further agitated with the further addition of 1 pound of:

copper sulphate, four pounds of calcium oxide, 0.4 pounds water gas tar, 0.2 pounds steam distilled pine oil, and 0.25 pounds of the same xanthate mixture, all per ton of ore, to yield a zinc-bearing froth concentrate.

The lead concentrate vwas then further agitated for ten minutes with the further addition of one pound ofv sodium cyanide and 0.2 pounds cresylic acid, both per ton of original ore, to yield a' finished lead concentrate and a lead middling. The zinc concentrate was further agitated for ten minutes with the further addition of 0.1 poundper ton of original ore of the same xanthate mixture to yield a finished zinc concentrate and a zinc middling. The results are shown in the following table:

In the following examples substantially pure alkaline earth metal xanthates were used.

Utah Copper Company ore was reground for fifteen minutes with five pounds of calcium oxide 'per ton of ore, made into a pulp with water, and agitated for fifteen minutes with 0.25 pounds of steam distilled pine oil, and 0.15 pounds of calcium xanthate, both per ton of ore, and a froth concentrate separated. The results are shown in the following table Assays 322;

On. On.

Per cent Per cent An almost equally good result was ob-..

tained in an acid pulp. The same ore ground for fifteen minutes without reagents, was made into a pulp with water and agitated for fifteerr minutes. with six pounds of sulphuric acid, 0.25 pounds steam distilled pine oil, 0.3 pounds calcium xanthate, and

' 0.05 pounds crude pine oil, all per ton of ore, and a frothrconcentrate separated. The results are shown in the following table:

Assays w Wt.

Cu. Cu.

Pcr cent Per cent Peicent Heads I 100 0.93 Cone 10. 6 7. 68 87. 5 Tall!" 89. 4 0. 13 12. 5

Table middlings from Doe Run mine of the Flat River district lead ore, containing blende and pyrlte, were reground for ten minutes in a ball mill, made into a pul with water, and agitated with 0.25 poun s of cresylic acid, 0.1 ounds of a saturated solution of sulphur ioxide, 0.7 pounds of coal tar creosote and 0.075 pounds of calcium xantha'te, all per ton of ore, froth concentrate. The remaining pulp was further agitated with the further addition of four pounds of calcium oxide, 1.5 pounds of copper sulphate, 0.3 pounds of water gas tar, 0.15 pounds of steam distilled pine oil and 0.1 pounds of calcium xanthate, all per ton of ore, to yield a zinc-froth concentrate.

The lead concentrate was further agitated with the further addition of 0.3 pounds of coal tar creosote, 0.05 pounds of calcium xanthate, and 0.3 pounds of sodium c anide, all per ton of original ore, to yield a nished lead concentrate and a lead middling. The zinc concentrate was further agitated with the further addition of four pounds calcium oxide and 0.015 pounds of calcium xanthate, both per ton of original ore, to 'yield a finished zinc concentrate and a zinc middling.

The results are shown in the following table:

Assays Recoveries Wt. Wt.

Pb .Zn. Fe. Pb Zn Fe Per Per Per Per Per Per cent cent cc cent cent cent Heads 959 100.0 9.22 11.29 10.8 Pb. C0nc 95 9.9 61.2 14.6 2.5 65.6 12.8 2.3 Pb. Midd- 100 10.5 19.4 25.0 13.4 22.1 22.3 13.0 Zn. Conc 95 9.9 1.8 62.0 1.7 1.9 54. 4' 1.5 Zn. Midd--.- 116 12. 1 5.0 6.0 32.5 6. 6 6.4 36.4 Tails 553 57.6 0.6 0.8 8.8 3.8 4.1 46.8

Results similar to those obtained with calcium xanthate were obtained with barium xanthate, except that in a pul acidified with sulphuric acidthe insolubi ity of barium sulphate seemed to interfere with the utility of a barium salt.

Utah Copper Company ore was ground in a ball mill for fifteen minutes with five pounds of calcium oxide per ton of ore, and made into a pulp with water. Thepul was then agitated for fifteen minutes wit 0.25 pounds of steam distilled pine oil and 0.2 pounds of barium xanthate, both per ton Table middlings from the Flat River district lea'd ore, 'containin blende and pyrite, were reg-round in a be to yield a lead- Doe Run mine of of saturated" sulphur dioxide solution, 0.7

pounds of coal tar creosote, and 0.15- pounds of barium xanthate, all per ton of ore, and a lead-bearing froth concentrate separated.

To the remaining pulp was added four pounds of calcium oxide, 1.5 pounds of copper sulphate, 0.3 pounds of water gas tar, 0.15 pounds of steam distilled pine oil, and

- 0.15 pounds of barium xanthate, all per ton of ore, and a zinc-bearing froth concentrate separated.

The lead concentrate was further agitated with the further addition of 0.3 pounds of coal tar creosote, 0.05 pounds of barium xanthate, and 0.3 pounds of sodium cyanide, all per ton of original ore, to yield a finished lead concentrate and a lead middling. The zinc concentrate was further agitated with the further addition of four pounds of calcium oxide and 0.03 pounds of barium xanthate both per ton of original ore, to yield a finished zinc concentrate and a zinc middling. The results are shown in the following table:

Assays Recoveries Wt. %Wt. l

Pb. Zn I Fe Pb. Zn. Fe.

Per Per Per Per Per Per cent cent cent cent cent cent Heads 980 100.0 9.11 10.9 I 10.8 Pb. Cone-.-" 100 10.2 60.8 12.4 4.7 68.2 11.6 4. 5 Pb. Midd 77 7.8 21.8 16.7 I 19.2 18.7 12.0 13.9 Zn. C0nc 114 11.6 2.0 57.6 3.0 2.5 61.5 3.3 Zn. Midd. 102 10. 5 5. 2 13. 7 23. 2 6. 0 13. 2 22. 6 Tails 587 59.9 0.7 0.3 10.0 4.6 1.7 55.7

Having thus described '7 certain embodiments of the invention, what is claimed is:

1. The process of concentrating ores which consists in agitating a suitable pulp of an ore with a mineral-frothing agent and enough of a material containing a substantial proportion of an alkaline earth metal xanthate to produce by the action of both a mineral-bearing iroth containing a large proportion of a mineral of the ore, and separating the froth.

2. The process of concentrating ores which consists in agitating a suitable pulp of an ore with a mineral-frothing agent and enough of a material containing a substantial proportion of calcium xanthate to produce by the action of both a mineral-bearing froth containing a large proportion of 'a. mineral of the ore, and separating the froth.

3. The process of concentrating ores which consists in agitating a suitable pulp of an ore with a mineral-frothing agent and with an alkaline-earth metal xanthate to produce by the action of both a mineralbearing froth containinga large proportion of a mineral of the ore, and separating the froth.

4. The process of concentrating ores which consists in agitating a. suitable pulp of an ore with a mineral-frothing agent and with a calcium xanthate to produce by the action of both a mineral-bearing froth containing a large proportion of a mineral of the-ore, and separating the froth.

In testimony whereof, I have afiixed my signature to this specification.

CORNELIUS H. KELLER. 

